Data to SPDIF conversion

I was thinking about connecting my audio system to my PC audio archives using Squeezbox (data to SPDIF only), but my pal suggested that XBox 360 can do the same (although it has Tosing only) plus lots of other useful things for about the same price, acting as Media Center Extension.

Is there any technical reason for it to be not as good in data => SPDIF conversion as Squeezebox?
I'll rephrase the question to be more general:
how significant amount of jitter may be introduced at data to spdif conversion stage, when it's happening in separate boxes like Squeezebox, Soundbridge, etc?
Is the idea to use the Xbox as the interface to your PC via Windows Media Center? You should take a close look at what that interface looks like and if it's the way you would want to access your music collection. And compare it to the Squeezebox interface.
Well, at this stage I'm more looking into factors affecting sound quality (i.e. jitter) for all available units, including SB.
The point is that if sound quality is comparable, some other units offer much better versatility.
Interesting, 2-3 years ago this place was much more active...
I think it's just that very few people have enough experience to comment. You ask a great question, though.